Thomas Smet
Veteran
There's now a Blackmagic eGPU Pro with an RX Vega 56 in it. https://www.apple.com/shop/product/HMQT2VC/A/blackmagic-egpu-pro
Yes which is finally a step in the right direction. Not entirely sure how much performance it would add over the rx580 in the iMac but hopefully somebody will test it out soon.
We have also been able to build a eGPU with the Vega 56 and 64 now for some time but the price was very high. The performance advantage really needs to be there to justify the extra cost of the Vega. This is why the top iMac is in an odd position. The GPU is good enough in the middle where it is harder to justify a eGPU right now even if one were to move to a Vega. Any lower GPU option should justify the Vega GPU but the 580 is fast enough where it becomes harder to justify the $1,200 cost to shave off a little bit of render time. It’s a bit like owning a gtx1070 in a PC and upgrading to the 1080. Yeah it’s an upgrade but was is really worth the cost?
I just don’t know enough about the performance gains of the Vega right now so maybe it really is a massive difference compared to the 580.